Grinding machine



Nov. 22, 1927.

F. E. GARDNER GRINDING MACHINE Filed June 5, 1921 2 Sheets-Sheet 1 \NveNToR fl/GWIZ-"E Gala/716p ATTY' Nov. 22, 1927.

F.., E. GARDNER GRINDING MACHINE 2 Sheets-Sheet 2 Filed Jun, 5. 1921 e um wafingwwu A'Uj's.

l'NvENTo 2 0 6 Patented Nov. 22, 1927.

UNITED" STATES I 'FREDERIC E. eanmvnn,

1,649,823 PATEN or BnLoIr, wIscoNsIN.

enmnnve MACHINE.

Application fil ed June 3,

and improvements in, construction, arrangement and operation which make the machine more desirable for certain classes of. work.

One of the important obj ects. of the inven- 15 tion is to provide an efiicientcarrier adapted to be recipr'ocatedto carry objects to bee ground between thev opposed overlapping grinding sections of annular grinding disks arranged-to rotate on parallel axes, the ob- 20 jects being fed to the carrier iatlone side of the grinding field and discharged therefrom at the other side. p

Afurther important object of the invention is to provide simple and eiiicient means for reciprocating the work carrier together with means for effecting such reciprocation intimed relation to the. separation of the grinding elements to successively receive. objects to be ground, the" arrangement being such that the work carrier travels to present an object between the grinding elements whensuch elements are separated so thatthe object will be-grounchwhen theelements are again brought together, in' proper grinding relationship. Q V

A very important feature in connection with the reciprocation producing mechanism is the variable motion given. to the work carrier. When the work receiving-opening is outside of the grinding field, the carrier moves very slowly andiis practically at a standstill for ashort perio'dgso-that ample time isgiven to readily and accurately insert an object "into the opening. .Thecarl 45 rie'r then travels slowly with slight accelerating movement while the object is carried to Ward and betweenthe overlapping grinding faces'so that ample timeisatforded for thorough and eiiicient grinding. The return movement of the carrier. is much more rapid and accelerated-so that the work' isquickly withdrawn from=between the grindiiigfaces, the movement then again slowingup as the opening reaches its outermost position.

Anotheraimportant object is to .provide 1921. S eriaI 1%. 474,585. I

improved dressing mechanismarranged to travel with the carrier to dres -the grinding faces of the grinding elements during operation of the machine so that such grinding faces will always be true and clean. I i I The above features and other improvements are incorporated in the machinedisclosed on the accompanying, drawings, in whichv Figure 1 is a side elevational view. I

.Zis a right'end elevational view, .F g, 3 1s a sectional view inline; 3-3, n j

Fig. 4 is. a sectional view on line 4-4, Fig. 2, and

plane 4; 4, of one. of the grinding wheel structures. I g,

In the structureshown, the machine base supports at itsopposite ends sub-base structures 11 and 12 on which are respectively mounted the carriages-13 and-14 for the annular grinding disks 15 and-16. The carriages-13 and-14 are of similar construction. ,Each is mountedon guideways 17 to be longitudinally shiftable or adjustableon the respective sub-base. Each has also journal. boxes :18 for journalling the grinding I wheel spindlei lt) which between thejournal boxes. carries the belt pulley 20 by means of whicht the spindle is rotated. At therinner end of each spindle is secured a head 19 in whichis seatedthe respective grinding disk 15 or.;1-6,-as clearly shown in Fig. 4;. The grinding disks are opposedto'each other and their spindles though parallel, are offset transversely of .themachine bed to the ex tent that the grindingelements overlaponly a distance equal to the radial width of the annulargrinding faces, as clearly shown in Fig.,3.

. The, carriages 13 andl l are adjustabletoward and away from each other for the purpose of adjustingthe gap between the grinding faces. .Any suitable means can be provided forfaccurately effecting such'adjustment.- The adjusting mechanism; disclosed in the. coj-pending application referred to may advantageously be used in my present machine. 7 r

" The work carrier shown is in theUform of a pla-te21 extending transversely of the machine in-a .ver'ticalpla'ne, and between the grinding elements At'its endsthe plate is secured on- -theIuprights 22 and'23 extending Fig. 5 isv an'enlarged sectional view, on

oriiflcfs from the ends of the base 24 slidably mounted on the rail 25 which is mounted on the wall 26 of the machine bed 10'. Strips 27 secured against the under side of the base 24 engage below the flanges 28 of the rail to keep the base in proper position on the rail during reciprocation of the carrier. The work carrier may thus be reciprocated transversely'of the machine between the grinding faces and the hole or pocket 29 in the plate 21 serves to receive and support objects to be ground. In the arrangement shown the objects are fed into the pocket when such pocket is outside of the grinding field and in front of the aperture of the annular disk 15. When the carrier is reciprocated the supported object is carried into position between the overlapping grinding faces where it is ground, and the object is ejected from the carrier when it arrives opposite the aperture of the grinding element 16. Objects can be fed into the carrier by hand or by suitable automatic feed mechanism.

Provision must be made to separate the grinding elements sufficiently to permit passage therebetween of the objects to be ground. Inthe machine shown the sub-base structure 12 is fixed against longitudinal movement on the machine bed but the subbase structure 11 is reciprocable so'that this structure canbe moved away or retracted from the structure 12 to thereby increase the space between the grinding elements. Such retraction'is automatically effected and in timed relation with the movement of the work carrier. At the'end of the machine base a bracket 30 journals the shaft 31 on which is secured the belt pulley 32. A worm 33 on this shaft mesheswiththe worm wheel 34 on the arbor 35 journaled in the extension 36 on bracket 30 and in the bracket 37 on the machine base. On the shaft 35 is also secured the cam disk 38 whichengages with the cam roller 39 on the lower'end of the lever 40 which near its upper end is pivoted on the bracket 41. At its upper end the lever is pivoted by means'of the pin 42 to the bracket 43 extending from the sub-base structure 11. Between the lower end of the lever andthe machine base is interposed a compression spring 44 which tends to swing the lever to cause the sub-base 11 to'shift inwardly. By means of a screw 45 the power of the spring 44 can be adjusted. The inward movement of the sub-base is limited by the stops 46 secured thereto and abutting against the machine base as clearly shown in Figs. 1 and 2. The contour of the cam 38 is such that its engagement with the cam roller will swing the lever to shift the base 11 outwardly against the force of the spring 44, and will then permit the spring to return the lever to gradually shift the carriage inwardly so that the grinding faces are gradually brought together after receiving an ob ject whereby the object is gradually ground to the degree desired, grinding stopping as soon as the stops 46 engage with the machine base. The grinding element 15 is thus positively shifted away from the element 16, but yieldingly though forcibly returned by the power exerted by spring 44 on the lever 40.

The mechanism for reciprocating the work carrier is clearly shown in Figs. 1 and 3. Secured to the under side of the work carrier base 24 is a rack 47 with which meshes a gear sector 48 trunnioned at its lower end in the bearing 49- secured on the machine base. A shaft 50 journaled in the bearings 51 and 52 has secured to its inner end the crank arm from which a crank pin 54 extends into the slot 55 provided in the gear 7 sector 48. The shaft 50 rotates .in clockwise direction and by virtue of the connecting pin and slot connection a very desirable variable speed of travel will be impartedto the work carrier. In the position represented in Fig' 3 a piece of work has just been inserted in the opening 29. As the shaft 50 rotates, the crank pin" 54' increases its distance from the axis of the gear sector and the carrier travels slowly to carry the work into position between the overlapping grinding faces, and such slow movement continues while the work is being carried along between these faces so that ample time is given forthorough and eflicient grinding. After the crank arm moving downwardly passes its horizontal position, the crank pin moves along the lower end of the slot and the speed accelerates, and such acceleration rapidly increases as the pin approaches the lower end of the slot, the result being that the ground piece of work is rapidly carried back through the grinding field, and as it leaves the field, the sector radius again increases and the carrier movement is slowed up until it reaches its outermost position. At the end of the movement of the carrier and just before it starts to travel inwardly a ain, it is practically at a standstill for a short period of time and ample time i'safforded to remove the finished work and to insert another piece. Very little time is therefore lost after a piece of work has been ground. The shaft 50'is driven from the shaft 31 from which the sub-base reciprocating mechanism receives its power and the work carrier will be reciprocated in timed relation with reference to the separation of the grind ing elements. As shown, the shaft 50 carries a bevel gear 56 which meshes with the pinion 56 on the shaft 35. By proper dimension and adjustment of these bevel gears theoperation of the work holder reciprocating mechanism with reference to the separation of the grinding disks may be deter mined.

During reciprocation of the carrier an ob- I "j ecfiinserted in the'pocket 29' will be carried in front of the apertures of the -annular CPI grinding disks and --to prevent objects from falling into such apertures and also to assist in guidingth'em into-the grinding field, I provide shields or disks .57 and 58in the respective apertures just'within' the inner 1 ground objects away from the grinding field;

end thereof (Fig. 4) 'Theseshields cooperate with the guide pla-tes 59 and 60 to guide objects into the grinding field between the overlapping grinding sections and to guide These plates 59 and 60 can be conveniently secured on the hood or housing structures 61 and 62 which are mounted .on the respective sub-base structures and surround the grinding wheel structures. The shield 58 maybe provided with a'discharge tongue 63 which engages with the finished objects as they are carried by and forces them out of the carrier pocket when they may be received on a suitable chute or conveyor (not shown).

The grinding elements are worn down during the process of grinding and also by dressing operation and the aperture shields are therefore made adjustable. In Fig. 5 an efficient adjusting arrangement is clearly shown. The shield is received between the heads 64 and collars 65 ofscrewsi66 which thread into the head 21 on which the grind:

ing element is mounted' By means of a screw driver or other suitable tool the screws true and clean, I provide dressing tools.

which I mount on the ends ofthe work carrier to be carried across the grinding elements as the carrier reciprocates On the upright 22 is mounted the dressing device for the grinding element 16 and onupright 23 is mounted the dressing device for the grinding element 15. Each comprises an arm 67 pivoted at its lower end to the upright and having at its upper end a split sleeve 68 for clamping the pin 69 which supports the housing 70 in which the dressing wheel or other tool 71 is journaled. The arm has the arcuate slot 7 2 for receiving the bolt 73 extending from the carrier upright, the nut 74 serving to lock the arm in any ad justed position. The upright has also a lug 7 5 through which extends the set screw 76 which engages with the upper end of the arm. The bolt 73 serves for preliminary adjustment and the set screw 7 6 for final adjustment of the dressing tools. On the drawing the tools'are shown withdrawn from the grinding elements. If it is desired to dress the elements the nuts 74: are loosened and the arms67 swung inwardly to carry the dressing tools to the grinding faces whereupon the nuts are tightened sufliciently to lock the arms. The set screws 76 are then shown the-dressing tools travel across? the grinding-faces of thejrespective elementsat points diametrically opposite to the overlappingsections of the elements. Dressing can thus be readily accomplished during operation of the machine. I By shifting the carriage 13inwardly compensation'is made forgrinding and dressing wear on the grinding disks. Worn out grinding elements ean be readilyreplaced, the rack and pinionconnection 77 permitting the sub-base structuer -11 to be shifted outwardlyafter removal of thefpin 42 so that ample space will be provided between the carriages 'for' substitution of grinding elements orfor other work. i a .1

I claim as my invention: 1. In a grinding machine of the class described, a rotary grinding disk, a work carrier and means for moving said carrier to present workto said disk at one side thereof, means for adjusting said disk on its support to compensate for wear, and means carried by said carrier for dressing saiddisk at another sidethereof, whereby the distance between the active grinding face and the work carrier will be maintained constant.

2. In a grinding machine of the class'de scribed, the combination of opposed annular rindin' disks a work carrier for car in g b 7 work through the grinding field between said disks, supporting heads for said disks, means for adjusting said heads to compensate for the grinding wear on said disks, and shields supported on said heads and positioned in the adjacent ends of said apertures, said shields being adjustable to maintain a guiding path of constant width between said disks for-the work to be ground.

3. In a grinding machine of the class described, the combination of opposed grinding elements, a reciprocating base, a work holding plate'mounted on said base to travel between the disks during reciprocation of the'base, said plate having means for supporting work to be ground, a rack on the underside of said plate a gear sector pivoted below said plate and meshing with said rack, a driving shaft, acrank arm thereon, and crank pin and slot connection betweensaid crank arm and gear sector whereby variable movements will be transmitted to said rack and the work.

4. In a grinding machine of the class described, the combination of opposed grinding disks,a work carrier reciprocable be tween said disks, a rack on said work carrier, a gear sector journaled below said rack and meshing therewith, and means for imparting variable rocking motion to said gear sector to cause said work carrier to travel faster in one direction than in the other.

5. Agrinding machine having, in combination, opposed grinding elements forming agrinding field, a reciproeatory member positioned at alltimes between said elements, means to automatically and periodically reciprocate said member to feed the work blank into saidgrinding field, and means for effecting an automatic axial reciprocation with one of said grinding elements from and toward the plane of said member in timed relation to the movementsof the lat-- ter. 1

6. A grinding machine having, in combination, an annular grinding disk, a Work carrier positioned to carry Work across said disk, a plate positoned in the opening of said disk to prevent Work from falling from said carrier into said opening, and means in said opening for supporting said plate,

said means-being rotatable with said grinding disk.

,c 7 A grinding machine having, in combination,an annular grinding disk, a Work carrier movable across said disk, a supporting head for said disk, a plate closing the opening in said disk against the entry of Work from said-carrier, and screw means secured to said plate and threaded into said head to support said plate, said screw means being adjustable in said head to adjust the position of said plate to compensate for Wear on said grinding disk, and being rotatable With said head.

In testimony whereof, I have hereunto set my hand. i

FREDERIG E. GARDNER. 

